MvvMCross UITableView bind local property to UITableViewCellAccessory.CheckMark - uitableview

Question

Hi I'm having an issue trying to bind MvxTableViewCell accessory Checkmark to a local property. I've tried following an example found at Bind MvxBindableTableViewCell's Accessory to boolean
I'm quite new to IOS and even newer to MvvmCross so I apologize if I've made any silly mistakes
public partial class TaxaListCellView : MvxTableViewCell
{
public static readonly UINib Nib = UINib.FromName ("TaxaListCellView", NSBundle.MainBundle);
public static readonly NSString Key = new NSString ("TaxaListCellView");
public TaxaListCellView (IntPtr handle) : base (handle)
{
Accessory = UITableViewCellAccessory.Checkmark;
SelectionStyle = UITableViewCellSelectionStyle.None;
this.DelayBind (() => {
var set = this.CreateBindingSet<TaxaListCellView, TaxonViewModel>();
set.Bind(lblSelectedTaxon).To(s => s.Name);
//I've been playing around with both ways below, and a few different
//variants without any success
//set.Bind("IsChecked").To(s => s.IsSelected).TwoWay();
//set.Bind(#"'IsChecked':{'Path':'IsSelected'");
set.Apply();
});
}
public bool IsChecked
{
get { return Accessory == UITableViewCellAccessory.Checkmark; }
set { Accessory = value ? UITableViewCellAccessory.Checkmark : UITableViewCellAccessory.None; }
}
public static TaxaListCellView Create ()
{
return (TaxaListCellView)Nib.Instantiate (null, null) [0];
}
public override void SetSelected (bool selected, bool animated)
{
Accessory = selected ? UITableViewCellAccessory.Checkmark : UITableViewCellAccessory.None;
base.SetSelected (selected, animated);
}
}
I'm not sure if there is anything wrong with my MvxTableViewController but here's the code
public class TaxaListView : MvxTableViewController
{
public TaxaListView()
{
Title = "Taxon List";
}
private UISearchBar _searchBar;
public override void ViewDidLoad()
{
base.ViewDidLoad();
_searchBar = new UISearchBar(new RectangleF(0,0,320, 44))
{
AutocorrectionType = UITextAutocorrectionType.Yes,
};
_searchBar.SearchButtonClicked += SearchBar_SearchButtonClicked;
_searchBar.TextChanged += SearchBarOnTextChanged;
var source = new MvxSimpleTableViewSource(TableView, TaxaListCellView.Key, TaxaListCellView.Key);
var set = this.CreateBindingSet<TaxaListView, TaxaListViewModel> ();
set.Bind (source).To (vm => vm.Taxa);
set.Bind (source)
.For (s => s.SelectionChangedCommand)
.To (vm => vm.ItemSelectedCommand);
set.Apply ();
TableView.RowHeight = 50;
TableView.Source = source;
TableView.AllowsSelection = true;
TableView.AllowsSelectionDuringEditing = true;
TableView.TableHeaderView = _searchBar;
TableView.ReloadData();
}
private void SearchBarOnTextChanged(object sender, UISearchBarTextChangedEventArgs uiSearchBarTextChangedEventArgs)
{
if(string.IsNullOrWhiteSpace(_searchBar.Text))
{
((TaxaListViewModel) ViewModel).SearchTaxaByText(string.Empty);
}
}
void SearchBar_SearchButtonClicked(object sender, System.EventArgs e)
{
((TaxaListViewModel)ViewModel).SearchTaxaByText(_searchBar.Text);
}
}
When I Select an item from the list first
When i start searching, Or happens even if i go back into the list of items

Answer 1

As Stuart alluded too, I needed to tell the ViewModel the value had changed.
I removed the SetSelelted method as this was causing problems when the cell was loading
public partial class TaxaListCellView : MvxTableViewCell
{
public static readonly UINib Nib = UINib.FromName ("TaxaListCellView", NSBundle.MainBundle);
public static readonly NSString Key = new NSString ("TaxaListCellView");
private const string BindingText = "Name Name; IsChecked IsSelected";
public TaxaListCellView() : base(BindingText)
{
Accessory = UITableViewCellAccessory.Checkmark;
SelectionStyle = UITableViewCellSelectionStyle.None;
}
public TaxaListCellView (IntPtr handle) : base (BindingText,handle)
{
Accessory = UITableViewCellAccessory.Checkmark;
SelectionStyle = UITableViewCellSelectionStyle.None;
}
public string Name
{
get { return lblSelectedTaxon.Text; }
set { lblSelectedTaxon.Text = value; }
}
public bool IsChecked
{
get { return Accessory == UITableViewCellAccessory.Checkmark; }
set { Accessory = value ? UITableViewCellAccessory.Checkmark : UITableViewCellAccessory.None; }
}
public static TaxaListCellView Create ()
{
return (TaxaListCellView)Nib.Instantiate (null, null) [0];
}
}
In My TaxaListView class
public override void ViewDidLoad()
{
base.ViewDidLoad();
_searchBar = new UISearchBar(new RectangleF(0,0,320, 44))
{
AutocorrectionType = UITextAutocorrectionType.Yes,
};
_searchBar.SearchButtonClicked += SearchBar_SearchButtonClicked;
_searchBar.TextChanged += SearchBarOnTextChanged;
var source = new MvxSimpleTableViewSource(TableView, TaxaListCellView.Key, TaxaListCellView.Key);
var set = this.CreateBindingSet<TaxaListView, TaxaListViewModel> ();
set.Bind (source).To (vm => vm.Taxa);
set.Bind (source)
.For (s => s.SelectionChangedCommand)
.To (vm => vm.ItemSelectedCommand);
set.Apply ();
TableView.RowHeight = 50;
TableView.Source = source;
TableView.AllowsSelection = true;
TableView.AllowsSelectionDuringEditing = true;
TableView.TableHeaderView = _searchBar;
TableView.ReloadData();
}
I Bind the selectedChangedCommand and in my ViewModel class I raise the Property changed event
private MvxCommand<TaxonViewModel> _itemSelectedCommand;
public ICommand ItemSelectedCommand
{
get
{
_itemSelectedCommand = _itemSelectedCommand ?? new MvxCommand<TaxonViewModel>(DoSelectedItem);
return _itemSelectedCommand;
}
}
private void DoSelectedItem(TaxonViewModel item)
{
Taxa.First(r => r.TaxonId == item.TaxonId).IsSelected = true;
RaisePropertyChanged("Taxon");
}